The present invention relates generally to a free falling locking tongue for a seat belt.
In many types of tongues for seat belt systems, belt slippage from the shoulder portion to the lap portion occurs during occupant excursion, which leads to an increase in the force on the shoulder portion of the belt and therefore an increase in occupant chest deflection. Locking tongues have been employed in certain seat belt systems. These tongues prevent the translation of the webbing from the shoulder portion to the lap portion and therefore reduces loading on the occupant's chest. In particular, the locking tongues are able to slide on the seat belt webbing to provide a proper fit over the occupant but are also able to lock or cinch the webbing during sudden deceleration of the vehicle to prevent loosening of the seat belt to properly protect the occupant.
Such locking tongues, however, have been used mostly in two point applications, since when used in three point applications, these locking tongues often result in a long piece of hanging webbing getting caught in the vehicle's door when it is closed because of poor free sliding performance of the tongue. Further, in these tongues, the seat belt webbing typically passes through an aperture in the tongue body and then wraps around a lock bar, which generates uneven load distribution across the webbing when the webbing is cinched or pinched between the lock bar and the edge of the aperture.